Prenatal screening methods are routinely employed to assess the likelihood of fetal abnormalities, commonly referred to as birth defects. For example, Down syndrome or Trisomy 21 is the most common cause of severe learning disability and accounts for approximately one half of all chromosomal anomalies in live born children.
Current methods to screen prenatally for trisomy 21 involve maternal serum testing for biochemical markers and/or ultrasound evaluation of biophysical markers. Maternal serum screening involves the quantitative analysis of biochemical markers and risk assessment based on likelihood ratios derived from the population distributions of affected and unaffected pregnancies. Ultrasound evaluation, however, has historically involved visual observation of a fetal image and deciding empirically whether the image looks “normal” or “abnormal” (for example, whether the cerebellum appears as a banana sign for open spina bifida). This approach requires extensive experience in the “art” of ultrasound and the interpretation is necessarily subjective.
Accordingly, there is a need in the art for a system and method that adequately evaluates the morphological changes observed with birth defects during prenatal screening.